Question: Determine how many solutions exist for the system of equations. ${6x+y = -3}$ ${-3x+y = -6}$
Convert both equations to slope-intercept form: ${6x+y = -3}$ $6x{-6x} + y = -3{-6x}$ $y = -3-6x$ ${y = -6x-3}$ ${-3x+y = -6}$ $-3x{+3x} + y = -6{+3x}$ $y = -6+3x$ ${y = 3x-6}$ Just by looking at both equations in slope-intercept form, what can you determine? ${y = -6x-3}$ ${y = 3x-6}$ The linear equations have different slopes. ${1}$ ${2}$ ${3}$ ${4}$ ${5}$ ${6}$ ${7}$ ${8}$ ${9}$ ${\llap{-}2}$ ${\llap{-}3}$ ${\llap{-}4}$ ${\llap{-}5}$ ${\llap{-}6}$ ${\llap{-}7}$ ${\llap{-}8}$ ${\llap{-}9}$ ${1}$ ${2}$ ${3}$ ${4}$ ${5}$ ${6}$ ${7}$ ${8}$ ${9}$ ${\llap{-}2}$ ${\llap{-}3}$ ${\llap{-}4}$ ${\llap{-}5}$ ${\llap{-}6}$ ${\llap{-}7}$ ${\llap{-}8}$ ${\llap{-}9}$ When two equations have different slopes, the lines will intersect once with one solution.